A neutral beam-assisted atomic layer chemical vapor deposition (ALCVD) apparatus is provided for uniformly depositing an oxide layer filling a planarization layer or a trench to increase uniformity and density of the oxide layer using neutral beams generated by a neutral beam generator without a seam or void occurring in an atomic layer deposition (ALD) or ALD-like chemical vapor deposition (CVD) process, thereby solving problems on the void or seam and low density occurring when a high-density planarization layer or a shallow trench having a width of 65 nm or less is formed, and improving a next generation oxide layer isolation process. The neutral beam-assisted ALCVD apparatus includes: an ALCVD apparatus, which deposits an oxide layer in order to form a pattern in a semiconductor substrate; and a neutral beam generator, which converts ion beams to neutral beams in order to remove a seam or void in the oxide layer deposited between the patterns, and applies the neutral beams to the oxide layer deposited to form the pattern.